From the main menu, go to: Training>Learn An Instrument>Pro Guitar>Medium Lessons>Power Chords. There are a total of 8 lessons that must be completed. The pause method used in Pro Keys Graduate can also be used for Pro Guitar lessons. Remember, ONLY the first run of a lesson will count using this method. So be sure to press left and right on the d-pad to reset the lesson if you make a mistake.

Fender Mustang players
If you are right-handed, try to strum each note with your thumb and keep your strumming hand as close as you can to the START and BACK section of the guitar. Once you strum each note, IMMEDIATELY use your pinky finger to pause the game. Make sure that your pinky finger is ALWAYS hovering over the START button before and after each note that you play. This will take a little getting used to. If you are left-handed, try pausing with your thumb and use your index finger to strum. This may feel awkward in either case and assigning a friend to press START for you is recommended.

Fender Squire players
You will need an extra person to pause the game between notes for you on your Xbox MIDI adapter. You can also try pausing with your foot if that doesn't seem awkward.

Below is a list of the chords that must be played for each lesson. This may look VERY intimidating, but it is pretty simple to understand. The numbers have been written to help players understand what must be played if the in-game instructions don't seem clear enough to follow.

The first number is the fret number (the number found on the top and at the bottom of the guitar). The second number is the string number within that fret that must be held (1 being the first string from the top and 6 being the last string). If there is a plus (+) then the fret numbers "added together" must be played at the same time. The third number (following the equal [=] sign) is the string that must be strummed to register the individual note or chord. Each set of notes that must be played is separated by an asterisk.

From the main menu, go to: Training>Learn An Instrument>Pro Guitar>Expert Lessons>More Chord Holding and Arpeggiation. There are a total of 5 lessons that must be completed. Below are two lists of notes. One list is chords-only for players who have learned how to read the individual notes between each chord. The second list is a list of all notes for each lesson:

This achievement will take quite a while for most players to finish. If you have learned the game's Pro guitar notation and can play and pause consistently without making mistakes or over strumming, this will take at least one hour to do. After all 5 lessons have been completed at 100%, the achievement will unlock.